NASA and Boeing Pivot X‑66 Program to Ground‑Based Thin‑Wing Tests

The partnership has decided to reorient the X‑66 project, which originally aimed to fly a full‑span aircraft, toward a ground‑based testbed that will examine the performance of long, thin wings. The change allows NASA and Boeing to concentrate on a technology that could be applied across many aircraft types. (Primary source)

All elements of the X‑66 design, along with any hardware that has been built or modified for the demonstrator, will remain in the program. Work on the flight demonstrator will pause while the ground tests continue, and the teams will still pursue research into the transonic truss‑braced wing concept. (Primary source)

The decision follows progress made since NASA awarded the Sustainable Flight Demonstrator project in 2023. Wind‑tunnel experiments, computational fluid‑dynamics simulations, and structural analyses have shown that thin‑wing configurations can offer substantial energy‑saving benefits. (Primary source)

Boeing identifies the thin‑wing design as broadly applicable, whether or not truss braces are incorporated. NASA’s broader goal is to boost next‑generation airliner efficiency, cut fuel consumption, reduce travel costs, and strengthen U.S. aviation leadership. (Primary source)